TNFRSF4 and neoplasm: In summary, bispecific trimerbodies have been effectively applied to the treatment of established tumors by tumor-targeted 4-1BB costimulation and comprise a novel technology platform for the future development of this and similar immunotherapeutic approaches, e.g., tumor-specific costimulation through CD40 or OX40, and combining PD-L1 blocking with costimulatory strategies.